Yamaha Outboard Problem After Carb Rebuild

[geoffschultz]

I'm in Panama trying to get my boat ready to depart for Honduras/Belize/Guatemala. My 15-HP Yamaha Enduro 2002 2-stroke outboard had been running sluggishly and decided to purchase a carb rebuild kit, which I installed before recommissioning the motor. The kit consisted of a new float, gaskets, needle valve and a few screws. I also removed the jets and cleaned them with carb cleaner.

When I fired up the motor it smoked like hell. I always fog the engine before storing it, but it didn't burn off like it did in the past. It's also *much* harder to start. I've had the carb off many times checking everything, but I can't see any issues.

However, I've noted that when I pressurize the fuel line with the bulb, that fuel comes out of the orifices circled in red below. The top left one is an actual hole into the card and the other 2 are brass something-or-others. I also see fuel spit out of the upper left hand hole and fizz out of the 2 brass ones when running the motor.

I suspect that this is the root cause of my issue, but I don't believe that I touched anything related to these. However, reality seems to be against me. Does anyone have any idea what's going on here and how to fix it?

Thanks, Geoff

 

[Bill Roosa]

Almost certain that the float is set wrong. fuel level in the bowl is too high. Requires a bending of the tang on the float that holds the float valve in its hole. Holding the carb float assembly with bowl off in its normal operating position gently push up on the float till it contacts the float valve and the valve closes. Now imagine the float being at a lower level and bend the tang to achieve that. Always seems backward to me. You might want to have a helper hold the float and valve closed while you take a measurement for the record. Good luck

 

[RussC]

Bill is correct. your float valve is leaking for sure. the hole you note is a bowl vent. fuel should not normally be nearly this high. was there a wire clip or "spring" holding the float needle to the float arm? if this clip is too tight on the float arm it can prevent the float valve from seating properly as well. the clip/spring is there to pull a stuck needle out of the seat if the fuel gels slightly, but they can also cause your issue if too tight. regardless… the float valve should be your focus.

 

[geoffschultz]

Thanks very much for your feedback. What's strange is that the float doesn't appear to be adjustable. It's all plastic. I'm going to replace the new float and the needle with originals in case there's something wrong/different with the new ones that aren't allowing it to seat properly. The old ones appeared to be in fine shape. Here's part of a photo that I took when reassembling the carb.

 

[RussC]

yup. non-adjustable and that saddle type float needle retainer isn't normally a problem. good idea to try the old ones in this case. also look closely to see if a chunk of dirt had gotten in under the needle.
Just to verify, both new and old needles are viton tipped…. correct??

 

[geoffschultz]

The issue was that the replacement needle didn't have the black plastic cap on it, which kept the float from pressing on the needle & caused the carb to flood. I hadn't realized that it was missing, so it was an easy fix.

Thanks for your insight!

-- Geoff